Single-Actuator-Based Three-DoF Planar Manipulation via a Viscoelastic and Nonparallel Hybrid Joint Mechanism

Abstract

This paper proposes a dexterous nonprehensile manipulation using the vibration of a plate, in which a three-degree-of-freedom (DoF) motion of a part is controlled based on a single actuator. First, a manipulator whose end effector is a flat plate is introduced. The manipulator employs a hybrid joint mechanism with a viscoelasticity and a nonparallel axis layout. The characteristic of the mechanism is that the shape, orientation, and size of the vibrational orbit of the plate vary based on the sinusoidal displacement input to the actuator. Subsequently, the trajectories of multiple point masses on the plate are analyzed to understand the approximated three-DoF motion of a part. The simulation results reveal that the whirlpool-like characteristics of the trajectory map, which aid in the rotational and translational motions of the part, can be managed by the input frequency, offset angle, and amplitude of the sinusoidal displacement input. Based on the trajectory maps, nine primitives for manipulating the part are designed. Finally, the proposed manipulation scheme is experimentally validated using a prototype. After confirming the nine primitives in the experiment, applications to one-DoF, two-DoF, and three-DoF parts feeding tasks are demonstrated.